1. Field of the Invention
This invention relates to plumbing fixtures and, more particularly, to fixtures such as sinks, lavatories and tubs having a polymeric shell with a relatively smooth polymeric top surface, a fiberglass or foamed polymeric reinforcing layer bonded to the underside of the shell, and a thermoformed polymeric cap bonded to the underside of the reinforcing layer to encapsulate the reinforcing layer between the underside of the shell and the cap.
2. Description of Related Art
Plumbing fixtures made of fiberglass and various other polymeric materials have become recognized and widely used in recent years as lower-cost alternatives to conventional fixtures made of cast iron, aluminum, porcelain, and the like. Such polymeric fixtures include showers, tubs, sinks and lavatories used in both residential and commercial construction and remodeling. Polymeric fixtures can comprise one or more polymeric materials including, for example, acrylics, polyesters, polyurethanes, other thermoplastic, cross-linked or thermosetting copolymers or terpolymers of resins and rubbers, such as acrylonitrile butadiene styrene (“ABS”), and other materials that are effective for use in particular applications or for achieving desired properties. Unlike cast metal fixtures, which generally have smooth undersides, polymeric fixtures often have rough, “chopped back” undersides.
Many plumbing fixtures, and particularly sinks, are made with a relatively smooth, top surface that is reinforced with a fiberglass backing comprising chopped fibers distributed throughout a polymeric resin matrix. Such backings are frequently applied using a “chop gun” that combines polymeric resin and a catalyst with chopped fiber roving that is sprayed through a nozzle onto a substrate. Catalysts such as organic peroxides are added to the polymeric materials to promote cross-linking, bonding, curing or hardening of the polymers. Such products are sometimes criticized by consumers and retailers because of the rough and unfinished look that is typically visible on the underside of sinks or other fixtures made in this manner. A new product configuration and method of manufacture are therefore needed that will enable polymeric plumbing fixtures such as sinks, lavatories and tubs to be made cost effectively and reliably, and with finished underlying surfaces that are strong but more attractive and easy to clean.